The inhalation dose rates and annual effective dose contribution from the mixed field of radon and thoron present in the environment of LPG bottling plant were measured, as it is very much essential from health and hygiene point of view of the workers in the plant. The radon and thoron concentration and the inhalation dose were found to vary from 7.78±2.02 to 59.01±5.57 Bq/m3, 1.16±0.28 to 65.08±5.09 Bq/m³ and 0.23 to 2.29 mSv/y, respectively. The concentration of radon daughters was found to vary from 0.84 to 6.38 mWL, the concentration of thoron daughters from 0.03 to 1.76 mWL, the annual exposure due to radon and thoron daughters, collectively, from 0.036 to 0.273 WLM, the life time fatality risk from 0.11 ×10⁻⁴ to 0.82 ×10⁻⁴ and the annual effective dose from radon and thoron (PAEC) from 0.14 to 1.06 mSv/y.